Deflector assembly for inboard power boats



April 28, 1964 s. BABBlT 3,130,541

DEFLECTOR ASSEMBLY FOR INBOARD POWER BOATS Filed Dec. 13, 1962 BOAT TR ANSOM INVENTOR/ SAMUEL BABBIT ATTORNEYS United States Patent 3,130,541 DEFLECTOR ASSEMBLY FDR INBOARD POWER BOATS Samuel Rabbit, 148-29 58th Road, Flushing 55, N.Y. Filed Dec. 13, 1962, Ser. No. 244,308 2 Claims. (Cl. 60-31) This invention relates to inboard power boats and, more particularly, relates to a deflector arrangement for alleviating the rise of steam and fumes at the transom.

In modern power boats, it is usual to provide an exhaust pipe to carry the exhaust gases produced by the engine such as a gasoline engine back through the boat and to pipe the fumes through the transom. The water utilized for cooling of the engine is conventionally piped through the same exhaust pipe also to be vented through the transom.

Since the fumes and the hot water are both conducted through the same pipe, the exhaust is hot and contains a considerable quantity of steam. These hot gases, steam and fumes tend to rise and as the boat moves forward, the back draft created by the transom will suck these gases into the cockpit of the boat. These arrangements make the cockpit extremely uncomfortable, in some cases, rendering the aft part of the cockpit so uncomfortable as to be unusable.

It is, therefore, an object of the present invention to provide a deflector arrangement which is insertable within the tail pipe of power boats to alleviate the rise of fume and steam at the transom.

-In accordance with this object, there is provided, in a preferred embodiment of this invention a deflector assembly comprising a formed sheet of material which can be inserted the exhaust pipe of a power boat. A plurality of deflector vanes are provided in the sheet of material. The deflector assembly is inserted within conventional tail pipes and is secured in position therein.

As the exhaust gases flow through the tail pipe, the deflector vanes break up the laminar flow thereby to cool the exhaust gases and substantially reduce and, in many cases, eliminate the obnoxious problem of steam and fumes over the transom of the boat.

Having briefly described this invention, it will be described in greater detail along with accompanying objects and advantages thereof in the following detailed description of the invention which may be best be understood by reference to the accompanying drawings, of which:

FIG. 1 is a sectional view of an exhaust pipe showing the deflector arrangement according to the present invention installed therein;

FIG. 2 is an end view of the arrangement shown in FIG. 1; and

FIG. 3 is a plan view of one form of deflector arrangement prior to assembly.

Referring to the figures, there is shown a tail pipe through which is vented the exhaust gases represented by arrow 1-2 and the heated water represented by 14 used for cooling the engine.

The deflector assembly 16 is installed within the exhaust pipe and is secured thereto. For example, the deflector assembly 16 may be formed of relatively thin maice terial so that it can be bent to fit the tail pipe and secured therein by bonding thereto as by epoxy bonding agent. Alternatively, set screws or clamps may be used to facilitate removal and reinstallation. The deflector assembly is provided with a plurality of deflector vanes 18 of semi-circular form extending perpendicular from the surface of the deflector assembly 16 and, thus, extending transversely to the axis of the exhaust pipe. These deflector vanes 18 may, for example, be approximately five-eighths of an inch in radius and are arranged in two adjacent staggered rows of one-foot in length. Such arrangement is preferably used in exhaust pipes up to about three inches. For larger exhaust pipes, the deflector vanes are preferably three-quarters of an inch in radius. Three rows may be utilized for the larger sizes although I have found that two rows give adequate operation in exhaust pipes up to four inches.

The vanes protrude into the stream of gases 12 which appear to be following laminar flow patterns at this point of the exhaust pipe. Because of this laminar flow, the hot gases have an opportunity to rise to the top of the pipe. These hot gases and the steam carried thereby will, thus, tend to immediately rise as the gases leave the exhaust pipe. However, with the protruding vanes, this laminar pattern is broken up and the hotter gases are mixed with the cooler gases adjacent the surface of the water stream 14. Although the exact reason is merely postulated, I have observed that the exhaust gases may be cooled down by as much as 90 F. in temperature with the assembly in place in contrast with the temperature of the same engine operating without the assembly in place. The cooler gases do not have the same tendency to rise, but will fiow out of the exhaust pipe and stay at the surface for a sufliciently long time to enable the power boat to travel away from the fumes before they rise.

The assembly may be prepared by die cutting the vanes 18 from a rectangular sheet of high-grade marine bronze such as an 55-5 composition. With such arrangement, the assembly may be formed to the size of the exahust pipe as it is installed.

Alternatively, the assembly can be cast in circular form in which case the assembly must be matched to the exhaust pipe diameter.

This invention may be variously modified and embodied within the scope of the subjoined claims.

What is claimed is:

1. A deflector assembly for insertion within the exhaust pipe of an inboard power boat through which is vented both engine exhaust gases and cooling water which comprises a plurality of deflector vanes positioned at the top of the inside of the exhaust pipe and extending toward the bottom thereof transversely across a portion of the upper part of the flow path in the pipe, said vanes extending into the flow path for at least of the pipe diameter, said vanes being arranged in staggered relation in parallel longitudinal rows.

2. An assembly in accordance with claim 1 in which said vanes are of semi-circular form.

No references cited. 

1. A DEFLECTOR ASSEMBLY FOR INSERTION WITHIN THE EXHAUST PIPE OF AN INBOARD POWER BOAT THROUGH WHICH IS VENTED BOTH ENGINE EXHAUST GASES AND COOLING WATER WHICH COMPRISES A PLURALITY OF DEFLECTOR VANES POSITIONED AT THE TOP OF THE INSIDE OF THE EXHAUST PIPE AND EXTENDING TOWARD THE BOTTOM THEREOF TRANSVERSELY ACROSS A PORTION OF THE UPPER PART OF THE FLOW PATH IN THE PIPE, SAID VANES EXTENDING INTO THE FLOW PATH FOR AT LEAST 1/6 OF THE PIPE DIAMETER, SAID VANES BEING ARRANGED IN STAGGERED RELATION IN PARALLEL LONGITUDINAL ROWS. 